KVM: PPC: Enable lightweight exits again

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The PowerPC C ABI defines that registers r14-r31 need to be preserved across
function calls. Since our exit handler is written in C, we can make use of that
and don't need to reload r14-r31 on every entry/exit cycle.

This technique is also used in the BookE code and is called "lightweight exits"
there. To follow the tradition, it's called the same in Book3S.

So far this optimization was disabled though, as the code didn't do what it was
expected to do, but failed to work.

This patch fixes and enables lightweight exits again.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

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Alexander Graf 2010-01-04 22:19:25 +01:00 • committed by Marcelo Tosatti

parent b480f780f0

commit 97c4cfbe89

2 changed files with 57 additions and 53 deletions

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4

arch/powerpc/kvm/book3s.c

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106

arch/powerpc/kvm/book3s_64_interrupts.S

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